Table 1 Comparison of Variables Included in Previous Econometric Crop Yield Modeling Research for Corn and Soybeans.
Studied Crops, Time Periods, and Regions | Estimation Method and Functional Form | Variables Included | ||||||
|---|---|---|---|---|---|---|---|---|
Weather | Price | Technology | CO2 | Land Quality | Groundwater Level | |||
This Paper | Corn & Soybeans 1950–2013: 29 counties in Ontario, Canada | Ordinary Least Squares (OLS) method Quadratic functional form | √ | √ | √ | √ | √ (FE/cropland area) | √ (FE/GW level) |
Houck & Gallagher (1976) | Corn 1951–1971: US | OLS method Linear functional form | √ | √ | √ | √ (Cropland area) | ||
Kaufmann & Snell (1997) | Corn 1969,1974,1978,1982, and 1987: counties in 8 states in the US | OLS method Quadratic functional form for weather | √ | √ | √ (Cropland area) | |||
Rickard & Fox (1999) | Corn 1889–1995: Ontario, Canada | OLS method Log-linear functional form Quadratic functional form | √ | √ | √ | √ (Cropland area) | ||
Schlenker & Roberts (2009) | Corn, Soybeans 1950–2005: counties on the east of the 100° meridian in the US | Nonparametric method Step functional form for heat 8th degree Polynomial for heat Piecewise linear functional form for heat Quadratic functional form for time trend | √ | √ | √ (FE) | √ (FE) | ||
Cabas et al. (2010) | Corn, Soybeans 1981–2006: 8 counties in southwestern Ontario, Canada | Feasible Generalize Least Square method Just and Pope production function | √ | √ | √ (FE) | √ (FE) | ||
Tolhurst & Alan (2015) | Corn, Soybeans 1955–2011: counties in Illinois, Indiana, and Iowa, US | Nonparametric method Quadratic functional form for precipitation | √ | √ | ||||
Miao et al. (2016) | Corn & Soybeans 1977–2007: counties on the east of the 100° meridian in US | Instrumental Variable method Quadratic functional form | √ | √ | √ | √ (FE) | √ (FE) | |
